The basic design of a water cooler is well known. With an increasing level of concern over the safety of much of the world's drinking water, the utilization of bottled water as a source of water for drinking, cooking and other applications has increased tremendously. Along with the increase in the use of bottled water there has been a significant advance in the design of water coolers and their component parts. For example, whereas initially such appliances were merely capable of dispensing water from an inverted bottle, today they commonly provide water that is chilled, heated and/or dispensed at room temperature. Further, others have developed a variety of different water bottle caps and mounting adapters to support bottles upon coolers that help to prevent spillage of water when inverting a filled bottle and placing it upon the bottle support structure. Still others have created structures that assist in sealing the cooler in order to limit or prevent the ingress of dirt and other debris that may contaminate water stored in the reservoir (see, for example, U.S. Pat. Nos. 6,167,921, 5,526,961, and 5,646,127 as representative examples of such devices).
While much has been accomplished in the design of water coolers to help prevent the contamination of water stored in the reservoir and to assist consumers in placing an inverted bottle onto the top of the cooler, little effort has been directed at a recurring problem that occurs when a bottle develops a small hairline crack or fracture in its outer surface. For obvious cost and weight benefits, most water bottles are formed from a relatively thin plastic material. When in use on a water cooler, the pressure differentials that the bottles are subjected to typically result in a flexing of the walls of the bottle, inwardly and outwardly as water is delivered to the reservoir and air is returned to the bottle. This flexing process can serve as a means by which small cracks or fractures in the bottle may develop over time. Even where a bottle shows no sign of leakage, when inverted and placed upon a cooler at some point during its use the bottle may develop a small crack or hole. The increased use of bottled water tends to exacerbate the problem since water bottles are continuously re-filled and re-used to the point that eventually they are prone to developing cracks in their side walls.
In the situation where an inverted filled bottle has or develops a small fracture or crack in its surface, the fracture presents an avenue by which air may enter the bottle, which in turn may cause the contents of the bottle to overflow the reservoir and spill onto the floor or surrounding surface area. In some instances the volume of water that can overflow the reservoir may be in the nature of a few gallons, which can cause substantial damage to flooring, furniture, and other surrounding items.
In an effort to combat this problem, others have incorporated within the reservoirs of water coolers small floats or bobbers that are meant to help reduce the flow of air into the reservoir. By reducing or slowing the flow of air into the otherwise sealed reservoir there is presented a means to at least partially control the flow of water from the bottle. Unfortunately, such existing devices are to a large extent ineffective in situations where a bottle develops a relatively small fracture that permits its contents to slowly be drained into the reservoir. That is, such existing devices tend to be somewhat effective in situations where there has been a significant breach in the wall of a water bottle but generally do not have the ability to positively and completely seal the reservoir air passageway where water slowly drains from a bottle that has developed a fine crack or fracture. Such prior devices also tend to be prone to becoming misaligned and may have a diminished effectiveness in situations where the water cooler is not vertically oriented.